Ground fault detection system for e.g. three phase electrical transformer, has detectors, and slide stressed by gravity towards active position, where each detector liberates slide from rest position during detection of ground fault

摘要

The system (20) has ground fault, level and pressure detectors, and a guide (24) i.e. vertical circular rod, extended between lower and upper ends. An electrically conductive slide slides on the guide between a rest position in which the slide does not touch electrical contacts (22, 23) i.e. multi-filament wires, and an active position in which the slide touches the contacts. The slide is stressed by gravity towards the active position and normally blocked in the rest position. Each detector liberates the slide from the rest position during detection of a ground fault. An independent claim is also included for an electrical transformer comprising a protection system.